dma.h

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/*
 *  arch/arm/include/asm/mach/dma.h
 *
 *  Copyright (C) 1998-2000 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  This header file describes the interface between the generic DMA handler
 *  (dma.c) and the architecture-specific DMA backends (dma-*.c)
 */

struct dma_struct;
typedef struct dma_struct dma_t;

struct dma_ops {
    int (*request)(unsigned int, dma_t *);      /* optional */
    void    (*free)(unsigned int, dma_t *);         /* optional */
    void    (*enable)(unsigned int, dma_t *);       /* mandatory */
    void    (*disable)(unsigned int, dma_t *);      /* mandatory */
    int (*residue)(unsigned int, dma_t *);      /* optional */
    int (*setspeed)(unsigned int, dma_t *, int);    /* optional */
    const char *type;
};

struct dma_struct {
    void        *addr;      /* single DMA address       */
    unsigned long   count;      /* single DMA size      */
    struct scatterlist buf;     /* single DMA           */
    int     sgcount;    /* number of DMA SG     */
    struct scatterlist *sg;     /* DMA Scatter-Gather List  */

    unsigned int    active:1;   /* Transfer active      */
    unsigned int    invalid:1;  /* Address/Count changed    */

    unsigned int    dma_mode;   /* DMA mode         */
    int     speed;      /* DMA speed            */

    unsigned int    lock;       /* Device is allocated      */
    const char  *device_id; /* Device name          */

    const struct dma_ops *d_ops;
};

/*
 * isa_dma_add - add an ISA-style DMA channel
 */
extern int isa_dma_add(unsigned int, dma_t *dma);

/*
 * Add the ISA DMA controller.  Always takes channels 0-7.
 */
extern void isa_init_dma(void);